Brake-applying means



May 9, 1933.

M. w. MC QZONKEY BRAKE APPLYING MEANS Original Filed Nov. 4, 1927 INVENTOR Patented UNITED STATES PATENT OFFICE MONTGOMERY W. MGCONKEY, OF SOUTH BEND, INDIANA, ASSIGNOR TOBENDIX BRAKE COMPANY, OF SOUTH BEND, INDIANA, A CORPORATION OF ILLINOIS BRAKE-APPLYING MEANS Application filed November 4, 1927, Serial No. 230,961. Renewed July 30, 1932.

This invention relates to brakes, and is illustrated as embodied in an internal expanding brake for a front automobile wheel. An object of the invention is to provide 17m- 6 proved means for adjusting the brake for wear, preferably automatically.

One feature of the invention. relates to the adjustment of the brake shoes, or equivalent friction means, to compensate for wear and preserve a predetermined clearance with respect to the brake drum when in released position, by means of one or more tension elements permitting a predetermined brakea plyin movement of the shoes and then 16 sl iifted lengthwise to adjust them. Freferably the cam or other applying device is held in engagement with the shoes, for example by a spring light enough to be overcome by the return sprin of the brake, so that the cam automatical y follows the adjusted released position of the friction means.

Whether or not the particular type of l brake adjustment described above is utilized, I prefer to provide one-way connection between an o erating lever, or an equivalent operating evice, and the applying devlce of the brake, for example by providing a roller clutch connecting the lever with the cam shaft of the brake. Thus the lever can operate the shaft in a brake-applying direction, but can move independently of the shaft to released position. This permits returning the lever to a predetermined released position, for example by a spring urging it against an adjustable stop, regardless of the brake adjustment.

The above and other objects and features of the invention, including various novel combinations of parts and desirable particular constructions, will be apparent from the following description of one illustrative embodiment shown in the accompanying drawing, in which:

Figure 1 is a vertical section through the upper part of the brake, just inside of the head of the brake drum, and showing the brake shoes in side elevation;

Figure 2 is a vertical section through the 60 upper part of the brake on the line 2-2 of Figure 1, and looking rearwardly at the ri ht front brake; and

igure 3 is a section through the operating lever on the line 33 of Figure 2.

The illustrated brake comprises a drum 10, rotatin with a wheel 12 mounted on a front knuc le 14 swiveled or pivoted in any desired manner at the end of the front axle 16. At the open side of drum 10 there is shown a backing plate 18 carried by the so knuckle 14. Wit in the drum are illustrated the upper ends of brake shoes 20, constituting the friction means of the brake, and which ma if desired, be formed and arranged su stantially as fully described in 05 Patent Number 1,567,716, granted Bendix Brake Company on December 29, 1925.

The shoes are forced apart, against the resistance of a return spring 22, by an applying device such as a cam 24, whlch may, if desired, be integral with a cam shaft 26 'ournaled in azbracket 28 secured to the backing plate 18 and having an operatingdevice such as a lever or crank 30. The brake as illustrated is intended to be applied by a 76 lever 32 fulcrumed on the axle 16 and having at its end an integral ball 34 engaging the lever 30 and arranged, when the brake is applied, with its center in or immediately adjacent the swiveling axis of the wheel.

n order to adjust the released position of the friction means, automatically to compensate for wear the shoes 20 may be provided with tension elements or links 36, formed with notches 38 permitting a predetermined brake-applying motion of the shoes without disturbing the setting of the elements 36. Elements 36 have their adjacent ends superposed (see Figure 2) and slotted to receive a nut and bolt, or other clamping means 40 frictionally holding the ends of these elements and resisting movement of them. As the shoes wear in service, the elements 36 are gradually shifted lengthwise outwardly to cause the spring 22 always to move the shoes 20 to released positions affording them a predetermined clearance with res act to the drum 10.

In order to hol the cam 24 or its equivalent always against the shoes, regardless of 100 their adjustment, I prefer to provide a torsion spring 44, connected at one end to shaft 26 and at its other end to bracket 28, and urging cam 24 in a brake-applying direction. Spring 44 is lighter than spring 22, and is therefore overcome by spring 22 when the brake is released, until the shoes 20 reach their released positions, but causes cam 24 to follow the adjusted positions of the shoes.

Lever is preferably connected to shaft 26 by a one-way connection such as a roller or Horton clutch 48, so that the lever operates the shaft whenever moved in a brakeapplying direction but can return to released or idle position independently of the shaft. Means, such as a spring connected at one end to lever 30 and at its other to the backing plate 18, serves to return the lever 30 to its idle position, and this ition may be determined by a device suc as an adjustable sto 52 threaded through a lug 54 on the bac ing late 18 and engaged by lever 30 when in rel ased position.

While one illustrative embodiment has been described in detail, it is not my intention to limit the sco e of the invention to that particular embo iment, or otherwise than by the terms of the appended claims.

I claim:

1. A brake comprising, in combination, friction means having oppositely-movable portions, a pair of tension elements operatively engaged and shifted lengthwise by said portions after a predetermined brakeapplyin movement, and means resisting any shi in of said elements.

2. A br e comprising, in combination, friction means having oppositely-movable portions, a pair of tension elements operatively engaged and shifted lengthwise by said portions after a predetermined brakeapplying movement, and a friction gripping device holding said elements.

3. A brake comprising, in combination, a retarding member, a tension element engaging said member and shifted len hwise by said member after a predetermine brakeapplying movement, a spring for restoring said member, and friction gripping device holding said element against shifting, said device exerting a frictional force suflicient to resist the restoring force of the spring but insufficient to resist the applying force of said member.

4. A brake comprising, in combination, a retarding member, a tension element engaging said member and shifted lengthwise y said member after a predetermined brake-applying movement, a spring for restoring said member, and a friction means yieldingly gripping said element and resists mg shifting 0 said element, said means exerting a frictional force suflicient to resist the restoring force of the spring but mosses said member.

5. A brake comprising, in combination, friction means, means determining the released position of the friction means and which is automatically adjusted by the operation of the brake to compensate for wear of the friction means, an applying device acting on the friction means, means constantly holding the applying-device in adjusted operative position with respect to the friction means in released position, an operating device for the applying device, and means for returning the operating device to a predetermined position when the brake is released, in'any adjustment of the applying device.

6. A brake comprising, in combination, friction means, means determining the released position of the friction means and which is automatically adjusted by the operation of the brake to compensate for wear of the friction means, a cam operatively en-.

gaging the friction means, a spring urging the cam angularly into constant engagement with the friction means regardless of its adjustment, an operating device for the cam, and means for returning the operating device to a predetermined position when the brake is released, in any angular released position of the cam.

7. A brake comprising, in combination, friction means, means for adjustably determining the released position of the friction means, a relatively heavy spring urging the friction means toward released position, an applying device, a lighter sprin urging the applying device in a brake-app ying directlon into engagement with the friction means, and an operating device for the applying device which is automatically returned to a predetermined initial position when the brake is released, independently of the released position of the applying dev1ce.

8. A brake comprising, in combination, a drum, friction means engageable with the drum, means for adjusta ly and automatically predetermining the released position of the friction means to give constant clearance with respect to the drum as the friction means wears, a spring ur ing the friction means toward the release position determined by the second means, a cam operatively engaging the friction means, a spring urgin the cam in a brake-applyin direction an which spring is weak enough to be overcome b the first sprin and an operating device or the cam whic is automatically adjusted to compensate for the turning of the cam in released position due to the adjustment of the released position drum, means for adjustably and automaticall predetermining the released position of t e friction means to ive constant clearance with respect to the rum as the friction means wears, a spring urging the friction means toward the released position determined by the second means, an applying device operatively en aging the friction means, a ring urging t eapplying device in a bra e-applym direction and which spring is weak enoug to be overcome by the first spring, and an operating device for the ap p ying device which is automatically adusted to compensate for the adjustment of the released position of the friction means.

10. A brake comprising, in combination, a drum, friction means engageable with the drum, means for adjustably and automatically predetermining the released position of the friction means to give constant clearance with respect to the drum as the friction means wears, a spring urging the friction means toward the released position determined by the second means, a cam operatively engaging the friction means, and a spring urging the cam in a brake-applying direction and which s ring is weak enough to be overcome by the first spring.

11. A brake comprising, in combination, a drum, friction means engageable with the drum, means for adjustably and automaticall predetermining the released position of t e friction means to give constant clearance with respect to the drum as the friction means wears, a spring urging the friction means toward the released position determined by the second means, and applying device operatively engaging the friction means, and a springurging the applying device in a brake-applying direction and which spring is weak enough to be overcome by the first s ring.

12. A brake-app ying device com rising, in combination, a brake applying s aft, a lever having operative connection with the shaft when moved in a brakeapplyin direction and movable independently of the shaft in the opposite direction, a device for limiting the movement of the lever in said opposite direction, and means yieldingly urging the lever in said opposite direction, to ether with a spring urging the shaft in a rake-applying direction as far as permitted by the brake in its released position.

13. A brake-applging device com rising, in combination, a ra e applying s aft, a lever having operative connection with the shaft when moved in a brake-applyin direction and movable independently 0% the shaft in the opposite direction, an adjust able stop for limiting the movement of the lever in said opposite direction, and means yieldingly urging the lever in said opposite direction, together with a s ring urging the shaft in a brake-applying direction as far as two points, said 'means comprisin permitted by the brake in its released position.

14. A brake comprising, in combination, friction means havmg oppositely movable portions and a pair of interconnected tension elements 0 eratively engaged and shift ed lengthwise said portions after a predetermined brali e a plying movement, and means comprising a olt resisting any shifting of said elements.

15. A brake comprising, in combination, friction means having oppositely movable portions, a pair of interconnected substantiall fiat striplike tension elements'operative y engaged and shifted lengthwise by said portions after a redetermmed brake applying movement an a friction gripping device com rising a bolt and nut construction for ho din said elements together and permitting sai lengthwise shiftmg.

16. A brake comprising, in combination, friction means having oppositely movable portions, said portions provided with fastening means projecting therefrom, a pair of tension elements operatively engaged and shifted lengthwise by said portions being connected to said fastening members, together with means including a bolt member passing through said elements, the latter being so constructed and arranged with respect to said bolt as to obviate reverse shifting of said elements.

17. A brake comprising, in combination, friction means havmg oppositely movable portions, a pair of stampings slotted at their ends and fitting in pro ections on said portions each of said stampin s having superposed slots at adjacent en s, together with a bolt member frictionally passing throu b said slots and frictionally grippin the si es thereof to hold said elements in t eir position of adjustment.

18. A brake comprising, in combination, a retarding member, a tension element engaging said member and shifted lengthwise by said member after a redetermined brake applying movement, said element being slotted at its end to accommodate a bolt member holding said element against shifting in the reverse direction.

19. A brake comprising a pair of shoes, means affordin a lost motion connection with each shoe or roperrelease movement, each means including a flat strip having a slot therein, common means passing through said slots for frictionally ho ding said strips to a sup ort.

20. A rake comprising a support, friction means, means having a lost motion can: nection with said friction means at at least overlapped stri s and adjusting means or frictionally ho ding said strips in overlapped position to said sup ort.

21. In a brake re ease positioning means w ll comprising a support, a pair of overlapped slotted strips frictionally secured to said support, and lost motion means adapted to connectsaid strips to a friction means.

' 22. A brake comprising a support, a friction shoe, a strip frictionalily secured to said support and ada ted for substantially radial and Iongitudinai movement for adjustment with respect to said support, and a lost motion connection means between said strip and said shoe to restrict clearance movement of said shoe.

23. In a brake release positioning means, a support, a pair of overlap ing strips, and means adapted to frictionaiiy engage said strips with said sup ort.

24. In a brake, a riction stop comprising an adjusting unit acting on two shoes for adjustment independent of each other.

25. In a brake, a friction sto compris ing an adjusting unit frictional y secured to a support and acting on two shoes for adjustment independent of each other.

In testimony whereof I have hereunto signed my name.

MONTGOMERY W. MOCONKEY.

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